How to properly set up TrueNAS with my rig.

[0x0539]

Hey there, new to the forums.

I was wondering what the best way would be to set up a TrueNAS, it will strictly be used for movie streaming for multiple users at once (4K movies/shows).
I want to install it on my rig that's on 24/7, I'll be running TrueNAS on a virtual machine (NVME M.2 SSD partition of 50GB).

Hardware I'll be using for it:
- 32GB RAM (or is 16GB enough?)
- 1x 1TB SSD (for cache?)
- 4x Seagate Barracuda 6TB 5200tpm (256mb buffer)

Is it overkill to have that much ram or an SSD for cache?
What kind of performance can I expect?

 

[Alecmascot]

Probably

- 4x Seagate Barracuda 6TB 5200tpm (256mb buffer)

Probably dire if those are SMR.

 

[Etorix]

Performance will depend whether this is a 4-wide Z2 or a stripe of mirrors.
A cache would only be useful if you expect to serve the same movie to different users. But you should increase RAM before setting up a L2ARC. A 1 TB L2ARC with only 32 MB RAM is likely to actually hurt performance.

 

[0x0539]

Performance will depend whether this is a 4-wide Z2 or a stripe of mirrors.
A cache would only be useful if you expect to serve the same movie to different users. But you should increase RAM before setting up a L2ARC. A 1 TB L2ARC with only 32 MB RAM is likely to actually hurt performance.

It will be set up in RAID 0

 

[jgreco]

It will be set up in RAID 0

Welcome to the forums.

ZFS doesn't support "RAID 0". Perhaps you meant striped. That's a bad idea, see below.

To help communicate more effectively and precisely on the forums, please review the Terminology and Abbreviations Primer.

Because if you meant that you intend to put 1TB of L2ARC on a 32GB system, as @Etorix already pointed out,

Performance will depend whether this is a 4-wide Z2 or a stripe of mirrors.
A cache would only be useful if you expect to serve the same movie to different users. But you should increase RAM before setting up a L2ARC. A 1 TB L2ARC with only 32 MB RAM is likely to actually hurt performance.

There is not sufficient ARC to support the L2ARC; generally, you want 64GB-128GB of RAM as a starting point to have sufficient ARC to do a good job of identifying stuff to evict to L2ARC, and if you are doing this for media, it is unlikely that even that amount of RAM would allow good selection for eviction for media, unless maybe lots of people were watching the same content at nearly the same time.

Also, you may have missed the equally correct and more dire warning,

Probably dire if those are SMR.

You do not want to use SMR drives on FreeNAS, especially if you are doing a striped pool with no redundancy. The loss of any device would result in the loss of your media collection.

I do not mean to steal the thunder from either @Etorix or @Alecmascot but I did want to fill in a little more detail.

 

[Etorix]

As far as reads are concerned, SMR drives will not hurt performance. They will hurt for writes, and quite possibly kill the pool in the event of a resilver—but with no redundancy any failure means the pool is lost, irrespective whether the drives are SMR or CMR.

If you need 24 TB of redundant storage (which will not be filled all the way up, of course) for the movies, you want 6*6 TB in RAIDZ2, to serve a limited number of concurrent users, or 8*6 TB drives in a stripe of four mirrors for a high number of users. If you're paranoid, make three-way mirrors. But don't forget the backup.

 

[jgreco]

I'm skeptical of the value of small hard drives. This last Black Friday, 14TB drives was where the value was, and 4 x 14TB disks in RAIDZ2 would give you 28TB with double redundancy. Had these been bought on Black Friday, shuckable from Best Buy, that'd have been about $760.